High-slip stretch film

ABSTRACT

A multi-layer stretch wrap film has three or more layers, including at least one outer non-cling layer, at least one inner core layer, and at least one outer cling layer, where the film displays enhanced non-cling properties after being stretched.

PRIORITY CLAIM

This application claims priority under 35 U.S.C. §119(e) to U.S.Provisional Application Ser. No. 61/785,480, filed Mar. 14, 2013, whichis expressly incorporated by reference herein.

BACKGROUND

The present disclosure relates to polymeric materials that can be formedinto a multi-layer stretch wrap film. More particularly, the presentdisclosure relates to a stretch wrap film that can be used to hold goodsto pallets during storage and/or shipping.

SUMMARY

A multi-layer stretch film in accordance with the present disclosureincludes three or more layers. The film has at least one outer non-clinglayer, at least one inner core layer, and at least one outer clinglayer.

In illustrative embodiments, a multi-layer stretch film in accordancewith the present disclosure has at least one first layer, which is anouter non-cling layer that includes a mixture of polyethylene andpolystyrene, at least one second layer, which is a core layer thatincludes at least one polyolefin, and at least one third layer, which isan outer cling layer that includes a polymer selected from the groupconsisting of polyethylene, plastomer, polyisobutylene, and mixturesthereof.

In illustrative embodiments, a multi-layer stretch film in accordancewith the present disclosure displays enhanced non-cling properties afterbeing stretched, thereby permitting thick films requiring substantialstretching force to be stretched that would otherwise slip throughstretching equipment without being stretched.

In illustrative embodiments, a multi-layer stretch film in accordancewith the present disclosure has a non-cling surface, which surfacegenerally does not cling to itself and prevents adjoining palletswrapped therewith from sticking together, and an opposing cling surface,which surface enables the film to stick to itself.

In illustrative embodiments, a multi-layer stretch film in accordancewith the present disclosure undergoes self-sealing when portions of thefilm are overlapped during the process of, for example, palletizingloads where it is desirable to hold or wrap an article(s) and/or holdgoods securely to pallets during subsequent storage and shipping.

In illustrative embodiments, a multi-layer stretch film in accordancewith the present disclosure optimizes physical properties therebyenabling such films to exhibit superior abrasion resistance in order toprotect wrapped contents from damage and exposure during shipment, goodcling in order to eliminate the need for taping of such films in orderto secure the contents, and good non-cling in order to prevent adjoiningfilm-wrapped pallets from sticking to one another.

Additional features of the present disclosure will become apparent tothose skilled in the art upon consideration of illustrative embodimentsexemplifying the best mode of carrying out the disclosure as presentlyperceived.

DETAILED DESCRIPTION

The present disclosure relates to stretch films with an optimizedbalance of beneficial properties. In particular, the stretch films ofthe present disclosure have a low coefficient of friction on their outernon-cling layer, thereby imparting superior non-cling properties, andsuperior abrasion resistance and cling properties, thereby rendering thefilms suitable for stretch-wrapping applications. Illustratively, thestretch films of the present disclosure have three or more layersincluding, but not limited to, a core layer, an outer or skin clinglayer and an outer or skin non-cling layer.

Illustrative embodiments of a multi-layer stretch film in accordancewith the present disclosure having five or fewer layers may berepresented by the construction A/B/C/D/E, wherein A is a cling layer, Eis a non-cling layer, and B, C, and D, which may be the same ordifferent polymer resins, are selected to optimize certain features ofthe core layer such as load containment, stretch, and punctureresistance while maintaining adequate tear propagation. An illustrativeembodiment with three layers may be represented by the constructionA/B/E, A/C/E, or A/D/E. An illustrative embodiment with seven layers maybe represented by the construction A/B/C₁/C₂/C₃/D/E. Those skilled inthe art will appreciate that various layer combinations and compositionsare possible. For example, an illustrative film A/B/C₁/C₂/C₃/D/E mayhave five identical core layers, i.e., B, C₁, C₂, C₃, and D areidentical, or five different core layers, i.e., B, C₁, C₂, C₃, and D areeach different, or three identical core layers, i.e., C₁, C₂, and C₃ areidentical and B and D are each different, and so on and so forth.Alternatively, a seven layer film may have four core layers, B/C₁/C₂/C₃,and two adjoining non-cling layers, DIE, and a cling layer A.

The total thickness or gauge of a multi-layer stretch film in accordancewith the present disclosure may vary depending on the intendedapplication for the film. It will be appreciated by those skilled in theart that the thickness of each individual layer may be similar ordifferent in addition to having similar or different compositions. Thethickness of each layer is therefore independent and may vary within theparameters set by the total thickness of the film. Illustratively, afilm having the construction A/B/C/D/E may preferably have correspondingpercentage by weight thicknesses of 10/15/45/10/20 of the totalthickness of the film. Alternatively, a film having the constructionA/B/C/D/E may preferably have corresponding percentage by weightthicknesses of 10/10/60/10/10 of the total thickness of the film.Further, a film having the construction A/B/C/D/E may preferably havecorresponding percentage by weight thicknesses of 5/10/50/10/25 of thetotal thickness of the film. The construction A/C/E may preferably havecorresponding percentage thicknesses of 10/70/20. The constructionA/B/C₁/C₂/C₃/D/E may preferably have corresponding thicknesses of10/15/15/15/15/10/20. Those skilled in the art will appreciate thatvarious layer combinations and thicknesses are possible.

The multi-layer stretch films in accordance with the present disclosureare typically manufactured by cast film or feed block co-extrusion.Alternatively, the stretch films of the present disclosure may be madeby blown film (tubular) co-extrusion. Methods for cast film, feed blockand blown film extrusion are disclosed in The Wiley Encyclopedia ofPackaging Technology, Aaron L. Brody et al. eds., 2nd Ed. 1997, pp.233-38, the disclosure of which is incorporated herein by reference inits entirety. Methods for film extrusion are also disclosed in U.S. Pat.No. 6,265,055, which is also incorporated herein by reference.

In an illustrative aspect, the cling layer of the multi-layer stretchfilm of the present disclosure enables the film to cling to itself whenthe film is wrapped on a load. The cling layer preferably constitutesfrom about 5% to about 40% by weight of the total thickness of the film,more preferably from about 5-15%, and most preferably about 10%. Thecling layer preferably contains one or more of ultra low densitypolyethylene (hereinafter “ULDPE”), very low density polyethylene,plastomer, polyisobutylene, linear low density polyethylene (hereinafter“LLDPE”), and mixtures or blends thereof. Due to the enhanced non-cling(i.e., high-slip) properties of the non-cling layer in accordance withthe present disclosure (see below), the cling layer preferably includesa ULDPE.

The cling layer may preferably contain from about 50% to 100%, morepreferably from about 60%-90%, and most preferably from about 70%-80% byweight of an ULDPE, which is also known as very low densitypolyethylene. ULDPE is ethylene copolymerized with at least one C₃-C₁₀α-olefin, more preferably a C₈ α-olefin. The resulting ULDPE preferablyhas a density ranging from about 0.885 g/cm³ to about 0.920 g/cm³, morepreferably from about 0.888 g/cm³ to about 0.910 g/cm³, and a melt indexranging from 1.0 g/10 min to 20 g/10 min, more preferably ranging fromabout 2 g/10 min to about 10 g/10 min. In a preferred embodiment, thecling layer contains about 80% of a ULDPE that is ethylene copolymerizedwith a C₈ α-olefin with a density of about 0.900 g/cm³, and a melt indexof about 5.

ULDPE can be produced by a variety of processes, including gas phase,solution and slurry polymerization as disclosed in The WileyEncyclopedia of Packaging Technology, Aaron L. Brody et al. eds., 2ndEd. 1997, pp. 748-50, which is incorporated herein by reference in itsentirety. ULDPE is typically manufactured using a Ziegler-Nattacatalyst, although a number of other catalysts may be used. For example,ULDPE may be manufactured with a metallocene catalyst. Alternatively,ULDPE may be manufactured with a catalyst that is a hybrid of ametallocene catalyst and a Ziegler-Natta catalyst. Methods formanufacturing ULDPE are also disclosed in U.S. Pat. Nos. 5,399,426;4,668,752; 3,058,963; 2,905,645; 2,862,917; and 2,699,457, the contentsof all of which are incorporated herein by reference in their entirety.The density of ULDPE is achieved by copolymerizing ethylene with asufficient amount of one or more monomers. The monomers are preferablyselected from 1-butene, 1-hexene, 4-methyl-1-pentene and 1-octene.

The cling layer may also include a plastomer in a range from 0% to about100% by weight of the cling layer, more preferably from about 70%-100%,and most preferably about 80%. The plastomer is preferably ethylenecopolymerized with a C₃-C₁₀ α-olefin, having a density in the range fromabout 0.850 g/cm³ to about 0.900 g/cm³, more preferably of about 0.860g/cm³ to about 0.880 g/cm³, and a melt index of about 1.0 g/10 min toabout 20.0 g/10 min, more preferably from about 2.0 to about 10.0 g/10min. The cling layer preferably contains about 70%-100% plastomer with adensity of about 0.875 g/cm³ and a melt index of about 3.0 g/10 min. Theplastomer is manufactured by the same process described above withreference to ULDPE, except that a higher amount by weight of one or moremonomers is copolymerized with ethylene. In an illustrative embodiment,the plastomer is ethylene copolymerized with a C₈ α-olefin, which has anunstretched cling of 250 g and a 200% stretched cling of 66 g asmeasured by ASTM D 4649. Cling is the strength required, in grams, topull apart overlapping film along a test section.

The multi-layer stretch films in accordance with the present disclosureinclude one or more core layers. The core layers or layer make up about50% to about 90% by weight of the thickness of the film, more preferablyfrom about 60-80%, and most preferably about 70% of the thickness of thefilm. Each core layer includes at least one polyolefin. Illustratively,each core layer may include an LLDPE in an amount ranging from about 97%to about 99.9% by weight of the core layer. Alternatively, each corelayer may include a blend of LLDPE and polypropylene. LLDPE ismanufactured by the same processes discussed above in connection withULDPE. For example, ethylene may be copolymerized using variouscatalysts such as a Ziegler-Natta catalyst or a metallocene catalyst, ora combination of the aforementioned catalysts. LLDPE has a higherdensity than ULDPE and plastomer because it is copolymerized with alower concentration of co-monomer than ULDPE or plastomer.

The LLDPE used in either the cling layer or the core layer is ethylenecopolymerized with one or more C₃-C₁₀ α-olefins, with a density rangingfrom about 0.900 g/cm³ to about 0.940 g/cm³, more preferably from about0.910 g/cm³ to about 0.930 g/cm³, and a melt index ranging from about1.0 to about 20.0 g/10 min., more preferably from about 1.5 to about 6.0g/10 min. Similar to the ULDPE discussed above, LLDPE used in the filmsof the present disclosure is preferably ethylene copolymerized with onemonomer of 1-butene, 1-hexene, 4-methyl-1-pentene, or 1-octene. LLDPEmay alternatively contain more than one co-monomer selected fromα-olefins such as 1-butene, 1-hexene, 4-methyl-1-pentene, and/or1-octene. The core layer preferably contains about 97% to about 99.9% ofLLDPE that is ethylene copolymerized with a C₈ α-olefin, with a densityof 0.917 g/cm³ and a melt index of 4.0 g/10 min.

Illustratively, each core layer may include a blend of LLDPE andpolypropylene. The polypropylene may be a homopolymer or may be theproduct of propylene copolymerization with a co-monomer, preferablyethylene. Alternatively, propylene may be copolymerized with anotherco-monomer, such as a C₃-C₁₀ α-olefin. The polypropylene of the presentdisclosure may be a copolymer of propylene and ethylene, the ethylenecontent ranging from 0 to about 10% by weight of the copolymer, or fromabout 2% to about 6% by weight. An illustrative embodiment has propylenecopolymerized with a mixture of α-olefins, the α-olefin content rangingfrom about 2% to about 4% by weight in a polymer known as randomcopolymer polypropylene. The random copolymer of polypropylene may havea density of about 0.905 g/cm³ and a melt flow rate of about 7.0 g/10min. The method for measuring polypropylene melt flow rate is disclosedin The Wiley Encyclopedia of Packaging Technology (Aaron L. Brody et al.eds., 2nd Ed. 1997), p. 677 and methods for manufacturing polypropyleneare disclosed in Kirk-Othmer Concise Encyclopedia of Chemical Technologypp. 1420-21 (Jacqueline I. Kroschwitz et al. eds., 4th Ed. 1999), thedisclosures of which are incorporated herein by reference in theirentirety.

The density ranges and melt indexes as disclosed herein for ULDPE andLLDPE and for plastomer and ULDPE partially overlap. However, thesepolymers may be further distinguished by crystallinity, measured as meltpoint. A ULDPE with the same melt index and density of LLDPE will have alower melt point than LLDPE as disclosed herein. Similarly, a plastomerwith the same density and melt index of a ULDPE, will have a lower meltpoint than ULDPE.

The multi-layer stretch films in accordance with the present disclosurefurther include a non-cling or slip layer that preferably makes up about5-40% by weight of the total film thickness, more preferably from about15-30%, and most preferably about 20%. The non-cling layer is preferablycomposed of a mixture of polyethylene and polystyrene. Thepolyethylene-based non-cling layer may have a density ranging from about0.890 g/cm³ to about 0.910 g/cm³, more preferably from about 0.895 g/cm³to about 0.905 g/cm³ and a melt flow rate from about 2.0 g/10 min toabout 40.0 g/10 min. In an illustrative multilayer stretch film, thenon-cling layer is preferably composed of from about 40-80% by weight oflow density polyethylene (hereinafter “LDPE”), from about 10-30% byweight of LLDPE, and from about 1%-25% by weight of polystyrene.

An unexpected feature of the multi-layer stretch films in accordancewith the present disclosure is their display of enhanced non-clingproperties (i.e., exceptional slipperiness) after being stretched. Moreparticularly, the stretch films described herein are not appreciablyslippery until after they are stretched, thereby permitting thick films(e.g., 3.0-mil films) requiring substantial stretching force (e.g., >200lb) to be stretched that would otherwise slip through stretchingequipment (without being stretched) due to inherent pre-stretchslipperiness. Multi-layer stretch films known in the prior art thatinclude polypropylene-based non-cling or slip layers display suchinherent pre-stretch slipperiness, rather than enhanced post-stretchslipperiness.

Illustratively, the LDPE of the non-cling layer may have a densityranging from about 0.900 g/cm³ to about 0.940 g/cm³, more preferablyfrom about 0.920 g/cm³ to about 0.930 g/cm³ and a melt index rangingfrom about 0.10 g/10 min to about 10.0 g/10 min, more preferably fromabout 0.3 g/10 min to about 0.7 g/10 min. LDPE is generally used forheavy bags, such as ice bags or shipping sacks, which normally have athickness of from about 1.5 mil to about 4.0 mil. A mil is a unit ofdistance equivalent to 0.001 inch (or 25.4 microns). As used in thenon-cling layer, the LDPE may be ethylene homopolymer or ethylenecopolymerized with one or more monomers, such as vinyl acetate, butylacrylate, methyl acrylate, acrylic acid, ethyl acrylate, or a C₃-C₁₀α-olefin. The LDPE is preferably ethylene homopolymer with a density ofabout 0.923 g/cm³ and a melt index of about 0.6-9.0 g/10 min. Analternative embodiment of the stretch film contains an LDPE that is acopolymer. Methods for manufacturing LDPE are disclosed in The WileyEncyclopedia of Packaging Technology, Aaron L. Brody et al. eds., 2ndEd. 1997, pp. 753-754, and in U.S. Pat. No. 5,399,426, the contents ofwhich are hereby incorporated herein by reference in their entirety.

The amount of each polymer included in the multi-layer stretch films inaccordance with the present disclosure is selected to create an optimalbalance of several physical properties. The stretch films describedherein balance increased load, holding containment and stretch withclarity, puncture resistance and resistance to tear propagation. Thestretch films described herein have a non-cling layer that includesLLDPE in combination with a large amount (relatively speaking) of LDPE.LDPE typically provides good load containment, stretch and necked-inwidth. The amount of LDPE in the non-cling layer is a substantialpercentage, however, i.e., in the range of 40% to about 80%, which wouldbe expected to reduce the film's puncture resistance, resistance to tearpropagation and clarity. It is thus also unexpected that the multi-layerstretch films of the present disclosure optimize load containment andstretch, while also optimizing puncture resistance and clarity.

The overall thickness of the multi-layer stretch films in accordancewith the present disclosure can be varied depending on the particularend use for which the film is manufactured. The stretch films of thepresent disclosure have a thickness that is generally in the range oftypical thickness for stretch wrap films, but may be easily adjusted byone skilled in the art to fit the desired end use. It has beendiscovered that the greatest benefits from the balance of properties ofthe present disclosure are found in gauges ranging from about 40 gaugeto about 500 gauge. Even more beneficial are the properties of the filmof the present disclosure at gauges ranging from about 60 gauge to about250 gauge. At these gauge ranges, it has been discovered that the filmperforms better than prior art films. Therefore, the films of thepresent disclosure preferably have a thickness ranging from about 0.4mils to about 5.0 mils and more preferably from about 0.6 mils to about2.5 mils.

Additives may be added to any of the film layers described herein inorder to improve certain characteristics of the particular layer or tomeet special requirements of specific applications. One or moreadditives may be added in amounts ranging from about 0%-99% by weight ofthe preferred first layer, second layer, third layer or other individuallayer, more preferably from about 0-10% by weight, and most preferablyfrom about 0.1-1.5% by weight. Illustrative additives include colorconcentrates, slip agents, antiblocking agents, fillers, and specialtyadditives for specific applications.

A color concentrate may be added to any of the film layers describedherein in order to yield a colored layer, an opaque layer, or atranslucent layer. Illustrative color concentrates include colorformulations including black, especially carbon black, white, and othercolors suitable for agricultural films such as those manufactured byAmpacet Corporation (Tarrytown, N.Y.). Illustrative color concentratesinclude Ampacet® white UV PE masterbatch, the carrier resin of whichbeing a LDPE having a melt index of 12 g/10 min at 190° C. and a densityof 0.916 gm/cm³ and the concentrate of which has a nominal specificgravity of 1.79, a melt index of 2-8 g/10 min at 190° C. and a pigmentcomposed of 65% TiO₂. Another illustrative color concentrate includesAmpacet® black PE masterbatch, the carrier resin of which being a LLDPEhaving a nominal melt index of 20 g/10 min at 190° C. and a density of0.92 gm/cm³. The concentrate has a nominal specific gravity of 1.15, amelt index of <6 g/10 min at 190° C., and a pigment composed of 40%carbon black. Another illustrative color concentrate includes Ampacet®black UV PE masterbatch, the carrier resin of which being a LDPE orLLDPE having a nominal melt index of 24 g/10 min at 190° C. and adensity of 0.92 gm/cm³. The concentrate has a specific gravity of 1.14,a melt index of 4-10 gm/cm³ at 190° C., and contains about 40% carbonblack. Any suitable color concentrate may be used in accordance with thepresent disclosure in order to satisfy particular requirements for afilm being produced in accordance with the present disclosure.

Illustrative slip agents include stearamide, oleamide, and erucamide. Aparticularly preferred slip agent is Ampacet® Slip PE masterbatch havinga LDPE carrier resin with an 8 g/10 min melt index at 190° C. and adensity of 0.918 gm/cm³. The slip agent's concentrate has a nominalspecific gravity of 0.92, a nominal melt index of 10-16 g/10 min andcontains 5% erucamide. Slip agents may be used alone or in combinationwith antiblocking agents. An illustrative slip/antiblock combination isAmpacet® Slip AB PE masterbatch having a LDPE carrier resin with an 8g/10 min melt index at 190° C. and a density of 0.92 gm/cm³. The slipagent's concentrate has a nominal specific gravity of 0.93, a nominalmelt index of 5-14 g/10 min at 190° C. and contains 2% slip agent and 2%antiblock. An antiblocking agent alone may also be added to a layer.Illustrative antiblocking agents include organic polymers such aspolyamides, polycarbonates, polyesters.

The present disclosure is further illustrated by the following examples,which are not to be construed in any way as imposing limitations uponthe scope thereof. On the contrary, resort may be had to various otherembodiments, modifications, and equivalents thereof which, after readingthe description herein, may suggest themselves to those skilled in theart without departing from the spirit of the present disclosure and/orthe scope of the appended claims.

EXAMPLES Example 1

A multilayer stretch film with superior cling and abrasion resistancehaving a total film thickness of about 1.0 mils was produced using theformula set forth in Table 1 wherein layer A is the slip or non-clinglayer, layer B is the core layer, and layer C is the cling layer.

TABLE 1 Formulation 1. Layer Ratio Wt % Type Mfr MFR MI Density A 20%60.0 Homopolymer Dow 8.7 Polypropylene 38.0 Random Dow 7.0 CopolymerPolypropylene 2.0 Polystyrene Dow 1.5 B 70% 95.0 LLDPE Voridian 4 0.9175.0 LDPE Dow 0.6 0.923 C 10% 100.0 Plastomer Dow 3.0 0.875

Example 2

A multilayer stretch film with superior cling and abrasion resistancehaving a total film thickness of about 2.0 mils is produced using theformula set forth in Table 2 wherein layer A is the slip or non-clinglayer, layer B is the core layer, and layer C is the cling layer.

TABLE 2 Formulation 2. Layer Ratio Wt % Type Mfr MFR MI Density A 20%60.0 Homopolymer Dow 8.7 Polypropylene 38.0 Random Dow 7.0 CopolymerPolypropylene 2.0 Polystyrene Dow 1.5 B 70% 95.0 LLDPE Voridian 4.00.917 5.0 LDPE Dow 0.6 0.923 C 10% 80.0 Plastomer Dow 3.0 0.875 20.0ULDPE Dow 5.0 0.900

A multilayer stretch film with superior cling and abrasion resistancewas produced using the formula set forth in Table 3 wherein layer A isthe slip or non-cling layer, layer B is the core layer, and layer C isthe cling layer. The film produced by formula 3, and in particular theslip layer, had inferior non-cling properties (i.e., slipperiness)compared to Formulae 1, 2, and 4 which were abrasion resistant.

TABLE 3 Formulation 3. Layer Ratio Wt % Type Mfr MFR MI Density A 20%100%  Random Copolymer Polypropylene B 70% 95% LLDPE Voridian 4.0 0.917 5% LDPE Dow 0.6 0.923 C 80% Plastomer Dow 3.0 0.875 10% 20% ULDPE Dow5.0 0.900

Example 4

A multilayer stretch film with superior cling and abrasion resistance aswell as enhanced post-stretch non-cling properties (i.e., slipperiness)having a total film thickness of about 1.0 mils is produced using theformula set forth in Table 3 wherein layer A is the slip or non-clinglayer, layer B is the core layer, and layer C is the cling layer.

TABLE 4 Formulation 4. Layer Ratio Wt % Type Mfr MFR MI Density A 15%69.5%  LDPE 20% LLDPE 10% Polystyrene 0.5%  Masterbatch B 75% 65% mLLDPE35% LLDPE C 10% 79.5%  ULDPE 20% mLLDPE 0.5%  Masterbatch

Example 5

A multilayer stretch film was produced using the formula set forth inTable 5 wherein layer A is the slip or non-cling layer, layer B is thecore layer, and layer C is the cling layer. The film produced by formula5 machined well but had inferior abrasion resistance (no abrasionresistance).

TABLE 5 Formulation 5. Layer Ratio Wt % Type Mfr MFR MI Density A 20%100%  LDPE B 70% 95% LLDPE Voridian 4.0 0.917  5% LDPE Dow 0.6 0.923 C10% 80% Plastomer Dow 3.0 0.875 20% ULDPE Dow 5.0 0.900

The foregoing description of illustrative embodiments of the presentdisclosure has been presented for purposes of illustration anddescription, and is not intended to be exhaustive or to limit thedisclosure to the precise form disclosed. The description was selectedto best explain the principles of the disclosure and practicalapplication of these principles to enable others skilled in the art tobest use the disclosure in various embodiments and modifications as aresuited to the particular use contemplated. It is intended that the scopeof the disclosure not be limited by the specification, but be defined bythe claims set forth below.

1. A multilayer stretch film, comprising: at least one slip layercomprising polyethylene and polystyrene; at least one core layercomprising at least one polyolefin; and at least one cling layercomprising ultra-low density polyethylene, very low densitypolyethylene, plastomer, polyisobutylene, linear low densitypolyethylene, or mixtures thereof.
 2. The film of claim 1, wherein theslip layer comprises about polyethylene in about 15%-99% by weight ofthe slip layer.
 3. The film of claim 2, wherein the polyethylene ishomopolymer polyethylene, copolymer polyethylene, or mixtures thereof.4. The film of claim 3, wherein the slip layer comprises homopolymerpolyethylene in about 40%-80% by weight of the slip layer.
 5. The filmof claim 4, wherein the slip layer comprises copolymer polyethylene inabout 15%-60% by weight of the slip layer.
 6. The film of claim 5,wherein the slip layer comprises polystyrene in about 1%-25% by weightof the slip layer.
 7. The film of claim 1, wherein the slip layerfurther comprises at least one additive selected from the groupconsisting of color concentrates, slip agents, fillers, specialtyadditives, and anti-blocking agents in about 0%-99% by weight of theslip layer.
 8. The film of claim 1, wherein the polyolefin in the corelayer is linear low density polyethylene, low density polyethylene,homopolymer polypropylene, copolymer polypropylene, random copolymerpolypropylene, or mixtures thereof.
 9. The film of claim 8, wherein thecore layer comprises linear low density polyethylene in about 97%-100%by weight of the core layer.
 10. The film of claim 8, wherein the corelayer comprises low density polyethylene in less than about 3% by weightof the core layer.
 11. The film of claim 1, wherein the core layercomprises at least one polyolefin in about 1%-100% by weight of the corelayer.
 12. The film of claim 11, wherein the core layer comprises ablend of polyethylene and polypropylene.
 13. The film of claim 11,wherein the core layer further comprises at least one additive selectedfrom the group consisting of color concentrates, slip agents, fillers,specialty additives, and anti-blocking agents in about 0%-99% by weightof the core layer.
 14. The film of claim 1, wherein the cling layercomprises ultra-low density polyethylene in about 1%-100% by weight ofthe cling layer.
 15. The film of claim 14, wherein cling layer comprisesultra-low density polyethylene in about 80% by weight of the clinglayer.
 16. The film of claim 1, wherein the cling layer comprisesplastomer in about 0%-100% by weight.
 17. The film of claim 16, whereinthe cling layer comprises plastomer in about 70%-100% by weight of thecling layer.
 18. The film of claim 1, wherein the cling layer furthercomprises at least one additive selected from the group consisting ofcolor concentrates, slip agents, anti-blocking agents, fillers, andspecialty additives in about 0%-99% by weight of the cling layer. 19.The film of claim 1, wherein the film has a gauge of about 40 gauge-500gauge.
 20. The film of claim 1, wherein the film has a gauge of about 60gauge-250 gauge.
 21. The film of claim 1, wherein the at least one sliplayer is about 5%-40% by weight of the film.
 22. The film of claim 1,wherein the at least one core layer is about 50%-90% by weight of thefilm.
 23. The film of claim 1, wherein the at least one cling layer isabout 5%-40% by weight of the film.
 24. The film of claim 1, wherein theslip layer has non-cling properties.
 25. The film of claim 1, whereinthe cling layer has cling properties.
 26. The film of claim 1, wherein asingle core layer is disposed between a single first layer and a singlethird layer.
 27. The film of claim 26, wherein the slip layer compriseslow density polyethylene in about 70% by weight, linear low densitypolyethylene in about 20% by weight, and polystyrene in about 10% byweight.
 28. The film of claim 27, wherein the core layer compriseslinear low density polyethylene in about 100% by weight.
 29. The film ofclaim 28, wherein the cling layer comprises ultra-low densitypolyethylene in about 80% by weight and linear low density polyethylenein about 20% by weight.
 30. The film of claim 1, wherein the film hasenhanced non-cling properties after being stretched.
 31. The film ofclaim 1 comprising additional layers, wherein each additional layercomprises at least one polyolefin.
 32. The film of claim 31, wherein thefilm has five layers or seven layers.
 33. A multilayer stretch film,comprising: at least one slip layer comprising about 70 wt % low densitypolyethylene, about 20 wt % linear low density polyethylene, and about10 wt % polystyrene; at least one core layer comprising about 65 wt %metallocene linear low density polyethylene and about 35 wt % linear lowdensity polyethylene; and at least one cling layer comprising about 80wt % ultra-low density polyethylene and about 20 wt % metallocene linearlow density polyethylene.